1. Technical Field
The present invention relates to a photoelectric conversion device, a method for manufacturing a photoelectric conversion device, and an electronic apparatus.
2. Related Art
Photoelectric conversion devices including a semiconductor layer composed of a CIS-based film or CGIS-based film with chalcopyrite structure are known (e.g., see JP-A-2012-169517). A photoelectric conversion device disclosed in JP-A-2012-169517 includes a lower electrode (first electrode), an upper electrode (second electrode), and a semiconductor layer (photoelectric conversion portion) provided between the electrodes. The lower electrode is formed of a high-melting-point metal such as molybdenum (Mo), and the semiconductor layer with chalcopyrite structure composed of a CIS-based film is formed on the lower electrode by a sputtering method.
Here, when the lower electrode made of a high-melting-point metal and the semiconductor layer with chalcopyrite structure are disposed in contact with each other as in the photoelectric conversion device disclosed in JP-A-2012-169517, the contact resistance between the lower electrode and the semiconductor layer is increased to deteriorate electrical characteristics, and thus there is a problem that the sensitivity of the photoelectric conversion device is reduced. Hence, if a surface layer portion of the lower electrode is selenized to forma selenized film, an ohmic contact is obtained at each of boundaries between the lower electrode and the selenized film and between the selenized film and the semiconductor layer, and thus the contact resistance between the lower electrode and the semiconductor layer is minimized. However, when the photoelectric conversion device includes a wiring portion, relay electrode, or the like that is formed of the same high-melting-point metal in the same layer as the lower electrode, a surface layer portion of the wiring portion or relay electrode is also selenized in the selenization of the surface layer portion of the lower electrode. Therefore, the wiring resistance is increased, and at the same time, the contact resistance between the wiring portion or relay electrode and an electrode in a higher layer is also increased, and thus there is a problem that the operation of the photoelectric conversion device may become unstable.